Announcement PDF RNS Number : 2190U East Star Resources PLC 10 September 2026 10 September 2026 East Star Resources Plc ("East Star" or the "Company") Gold Exploration JV Update East Star Resources Plc (LSE: EST), the Kazakhstan-focused gold and copper exploration and development company, is pleased to provide an update on its gold exploration joint venture ("JV") with Endeavour Exploration Limited, a subsidiary of Endeavour Mining plc (LSE: EDV, TSX: EDV) ("Endeavour"), one of the world's leading gold producers and a constituent of the FTSE 100 Index. Under the strategic joint venture agreement announced on 13 November 20251 , Endeavour has the right to earn a 51% interest in the JV by funding US$5 million of qualifying exploration expenditure during the Stage 1 earn-in period of two years, which commenced on 15 May 2026. Since the establishment of the JV, East Star and Endeavour have made significant progress in establishing the technical and operational platform for systematic gold exploration across the two Areas of Interest located in the north of Kazakhstan on the highly prospective Kazakh orocline, totalling >300,000km2 . Key work completed to date includes: · Completion of field visits and geological reconnaissance across 15 priority targets within the Areas of Interest. · Submission of several new exploration licence applications, covering in excess of 930km2 and focussed on Intrusion Related Gold systems within the northern Area of Interest (See Figure 1 below). · Establishment of the JV's in-country technical and operational team with staff now including two senior geologists and four junior geologists. · Compilation and review of historical and modern geological and exploration datasets. Work has included collection of the 1:50k geological, mineralogical and geophysical maps as well as Soviet exploration reports across the licence areas with AI assisted translation and spatial searchability functions, developed with partners, used to quickly search at scale easily, in Russian or English, across historical data. · Commencement of large-scale review of geotectonic setting of mineral provinces within the Areas of Interest using a hybrid traditional and AI assisted system for prospectivity mapping. This targeting framework will allow for better targeting of multiple ore systems including Intrusion Related Gold (IRG), porphyries, epithermal systems and skarns. With the operational framework now in place, the JV will progress into more systematic field exploration, including geological mapping, soil and geochemical sampling once licence applications are granted. Alex Walker, CEO of East Star Resources, commented: "The joint venture has been fully established and is moving into systematic exploration. We have completed considerable work programmes across data compilation, field reconnaissance, licence applications, staffing, equipment and funding. With several licence applications submitted in the northern Area of Interest, our focus is increasingly shifting towards field exploration and systematic testing of the most prospective gold targets." Figure 1 - The major gold deposits and producing regions of Kazakhstan as well as the two Areas of Interest covered under the Endeavour JV. Intrusion Related Gold (IRG) Systems Intrusion Related Gold (IRG) systems are a genetically distinct class of gold deposit in which a single fertile, reduced igneous intrusion acts simultaneously as both the source of the gold and the hydrothermal fluid. Mineralisation is spatially and temporally linked to I-type, ilmenite-series granitoids emplaced in post-collisional or extensional continental settings. The deposits display characteristic pathfinder zoning outward from the intrusive core with proximal tungsten and molybdenum, through gold and bismuth, to distal silver-lead-zinc expressions. This style of deposit includes some of the world's largest gold deposits including Vasilkovskoe, on the same belt in northern Kazakhstan, with total mineral resources of >15 million ounces (2011)2 . Vasilkovskoe is a classical IRG deposit hosted within Palaeozoic rocks associated with the fertile magmatic suite the JV is targeting. IRG deposits are compelling exploration targets because the causative plutons are detectable at belt scale through regional geophysical and geochemical surveys, systematically narrowing the search space before field programmes begin. With Kazakhstan's Palaeozoic belts sharing the same post-collisional tectonic architecture and magmatic age window as established IRG provinces globally, the geological setting is demonstrably favourable for the discovery of further deposits. 1 https://www.londonstockexchange.com/news-article/EST/25m-strategic-jv-agreement-with-endeavour-mining/17324614 2 Newell et al., 2011 - Competent Person's Report for the Assets held by Kazzinc Limited in Kazakhstan and Russia; prepared by Wardell Armstrong International, Truro, UK To watch a video of Alex Walker discussing this announcement, visit: https://eaststarplc.com/link/rJEg5e Contacts: East Star Resources Plc Alex Walker, Chief Executive Officer Tel: +44 (0)20 7390 0234 (via Vigo Consulting) SI Capital (Corporate Broker) Nick Emerson Tel: +44 (0)1483 413 500 Vigo Consulting (Investor Relations) Ben Simons / George Pope / Georgina Moul Tel: +44 (0)20 7390 0234 About East Star Resources Plc East Star Resources is focused on the discovery and development of copper and gold in Kazakhstan. The Company' key interests are: · A joint venture with Hong Kong Xinhai Mining Services Limited to take the Verkhuba Deposit (20.3Mt @ 1.16% copper, 1.54% zinc and 0.27% lead) into production (at no further cost to East Star) with East Star retaining 30% ownership in production · A joint venture with a Kazakh mining company to develop the Rulikha project, (exploration target of 23Mt @ 2.4% copper equivalent) into production (at no further cost to East Star) with East Star retaining between 25% and 35% ownership in production · A $25 million+ strategic gold exploration joint venture with FTSE 100 Endeavour Mining · Tier 1 potential copper porphyry and epithermal gold targets in a proven belt Visit our website: www.eaststarplc.com Follow us on social media: LinkedIn: https://www.linkedin.com/company/east-star-resources/ X: https://x.com/EastStar_PLC Engage with us by asking questions, watching video summaries and seeing what other shareholders have to say. Navigate to our interactive Investor Hub here: https://eaststarplc.com/link/rJEg5e Subscribe to our news alert service: www.eaststarplc.com/newsalerts About Endeavour Mining plc Endeavour Mining is one of the world's senior gold producers and the largest in West Africa, with operating assets across Senegal, Côte d'Ivoire and Burkina Faso and a strong portfolio of advanced development projects and exploration assets. A member of the World Gold Council, Endeavour is committed to the principles of responsible mining and delivering meaningful value to people and society. Endeavour is admitted to listing and to trading on the London Stock Exchange and the Toronto Stock Exchange, under the symbol EDV. The person who arranged for the release of this announcement was Alex Walker, CEO of the Company. 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